braun



Nov. l0, 1964 o. l.. BRAUN 3,156,218

FORCED CIRCULATION WATER-COOLED FURNACE DOOR Filed Oct. 2. 1961 MUNI im#INVENTOR.

OTW/N L. BRAUN www A TTORNE YS United States Patent Oifce 3,156,2l8Patented Nov. 10, 1964 Ottnln l.. llrnun. l'lthhurph. l'n., nsslzznnr toReliance Steel Products Company` hiclecsport, la., n corporation ol'Pennsylvania Filed Oct. 2, i961. Ser. No. 141,371 2 Clnlmfl (Cl.122-498) This Invention relates to a forced circulation watercooledfurnace door nnd. more particularly. to a furnace door having structuralmembers which both .ftrengthen and serve as fluid conduits to'cool thedoor.

Open-hearth furnace doors arc generally exposed to the intense heat ofthe furnace combustion zone. and to teuer withstand the high temperatureexposure a refractory linlng is positioned on the door inner face. lthas l-een found nccenary ln order to prevent heat destruction of thelining to cool the door and lts lining ly circulating water between themetal portion of the door. which anrmally is provided with an integralreservoir. and the lining. Studs or tubes are embedded within therefractory material. and water ls circulated through these tubes to andfrom the reservoir ln the metal or main body por tlnn of the door.'l'hcse tubes are fastened to the door main body portion in such amanner that th: tulcs anchor the refractory lining onto the door innerface.

llcretofore. the refractory lined. water-cooled doors had a useful lifewhich was seriously limited hecause of the incfllcieney of the doorcooling system. That is. thi.` water contained within the main bodyportion and the tuhes within the refractory lining rapidly become heatedto an elevated temperature. Circulating this heated water between thejacket or reservoir and within the tubes failed to maintain thetemperature of the refractory material and the door metal to the lowlevel or decree required to eliminate the destruction of the materialscomprising the door.

ln my copending npplleation Serial No. 142.276 for a Forced CirculationWater-Coolcd Door. filed October' 2.

i96l, which is assigned tn the assignee of the instant application.there is provided n plurality of tubes which lock the lining in positionon a furnncc door. and which form n part of n forced circulationwater-cooling system. Water' is introduced into the door under pressure.and n constant volume of cool water ls forced through the doorcoolingsystem. The water ls continuously forced out of the door nl n rnle offlow which maintains the temperature of the water within n designedrange. As a result of the forced circulation of water in the novel doorcool ing system. thr.` service life of the door ls prolonged for aperiod exceeding that of the prior nrt doors.

This invention utilizes the forced circulation principle for cooling nfurnace door much the same as that dis closed and claimed in myabove-cited copcnding application. The general nature of the opcn-hcarthfurnace door is well known to include an inner and an outer facc whichnre in parallel spaced relationship. The marginal portions of both doorfaces are flanged. with the inner face flange being iaturned to form asupporting surface for a refractory lining which is cast in situ on thedoor inner face. Tite flanges nrc joined together at their edges withone flange being directed toward the other such that thc flanges on thefaces of the door are spaced apart to Iitl form a water jackct orreservoir. Tubes. hollow studs` or other conduit members extend from thedoor inner face into the lining and hold it in place on thc door innerface. The door jacket and tubes are filled with water. and in the` knowndoors. the water is circulated hy convection current to and from-thejacket through the tubes.

An object ofthe present invention is to provide n forced circulationwater-cooled furnace door having n monolithic refractory lining securedon the door inner face hy emlcdded hollow keys arranged on the door tofurnish maximum support for the lining.

Another object is the provision of a watercooling system for a furnacedoor having hollow elements which support a refractory lining on thedoor a'rd which are designed to conduct water under pressure through thesystem to achieve maximum cooling eflciency.

A forced circulation water-cooled furnace door illustrating certainfeatures of the present invention may in clude a door having a waterchamber and refractory lining as above-described and having doorreinforcing hollow keys which are embedded within the refractory lining.The keys are connected to a water inlet for receiving water underpressure. and empty into the door water chamber from which the water isexhausted through an outlet passing through an inner face flange.

A complete understanding of the invention may lie had front thefollowing detailed description of n specific. cnibodiment thevrof whenread in conjunction with tho appended drawings. wherein:

FIG. l is an elevational view of the door inner face without therefractory lining applied thereto;

FIG. 2 is a longitudinal crossscction of the door taken along thevertical centerline ll-ll of FIG. l. with rcfractory material in placeon the door inner face;

FlG. 3 is an enlarged fragmentary cross-sectional view of the door takenalong line lll--lll of FIG. l which illustrates the connection of alransvcrse hollow rib with n channel;

l-`lG. i depicts in an enlarged fragmentary cross sectional view takenalong line lV--lV of FIG. l a connection between a vertically extendinghollow rih and a water chamber; and

FIG. 5 shows the coupling of an inlet pipe and u channel in ncross-sectional view taken along line V-V of FIG. l.

Referring to the drawings. wherein like reference charnclcrs designatelike or corresponding parts throughout the .several views. thereV isshown in FIGS. l and 2 n furnace door generally designated number Il. Anouter door face l2 of heat resistant metal. for example. has itsmarginal portions 1.1 turned rearwardly to form n continuous peripheralflange 14. Latcrally spaced from thc outer face l2 and in parallelrelationship therewith is a door inncr face 15 having its marginalportion 16 directed rearwardly. inwardly, and then outwardly to form aflange 17.

As best shown in FIG. 2. thc parallel spacing of thc faces and theirflanges defines the formation of a water jacket 18 within which arearranged transverse channels 19 having their edges scaled ftxedly to thcdoor inner face l5. The channels 19 nrc of suflicicnt length to eztstend or to overhang the water jacket flange portion 2l. I"lG. 5. and arecach connected to a water inlet pipe 2.. located in the portion 21 by aconduit 23. A duplicate water pipe 22 is located in the jacket portion2l on the left side of the door ns viewed in FIG. l: as circum- .stancesdictate. the water may be introduced into lh.` door from either one orboth of the pipes 22. The lower end 24 of each pipe 21 is restricted indiameter and open .such that cool water may le forced directly towardthe bottom of the door ll. At the .same time. water is fed through theconduits 2J to transverse channels lf) without nn appreciable loss ofwater pressure in the channels l) caused by the feeding of water throughthe open end 24 ofthe pipe 22. Clean-out plugs 2S are located inthelowermost corners 26 of the door ll.

Keys or ribs 27 are positioned on the door inner face l5 and are joinedat their ends 28 tothe flanr'e t7 of the inner face l.'-' The keys orrihs 17 are trapcroidal in crmvscclion. i510. 4. and extend across theinner fave l5 from the inner fiance 17 at one location to the innerflange t7 nt an opposed location. as shown in tt( t` Similar keys orribs 19 are arranged between the two substantially transserse tihs 27.and between the upper farms-ene rih and the inncr flange 17. iloth ribs2') are closed at their upper and lower ends .il hy their rigidconnection with the flange t7 and with the rihi 17.

The small structural channels ll communicate with the two transverseribs 27 via apertures .l1 passed through the inner face or plate l5. andthe rihs 27, in turn. opsn into the water jacket flange portion 2tthrough suitable ports JJ through the inner flange t7. The water jacketI8 is flow-connected to the vertical keys or ril-s 1*? through verticalslots M prosded thronph the inner face l5. Water outlets JS extendthrough the door outer flange i7 into the jacket lll.

The tratto-cru: rihs 27 are upwardly inclined from their midpoint. forexample. toward the flange i7 with the lowermost point being at thejuncture of the rils 27 willi the structural channels l). The recess.ifi letcrern the tlOOr inner llattjte i7 is filled with n refractorymaterial J7. which is cast ln situ and hardened within the recess. Asshown best in FIG. 5. the inner flange 17 ovcrhane the material J7 atits periphery which contacts the flange, thus supporting the lining .ltlwithin the rece in sonic measure.

The hollow keys 27 and 29 provide the maximum support of the lining .lllonto the inner face l5 within the rece J6 hy virtue of the trapemidalcroswection of the keys nnd their special arrangement on the inner face.The upwardly extending transverse keys 27 sustain the lining JB on theinner face t5. and combined with the vertical keys 29. maintain thelining rigidly on the door. The heya are embedded within the material J7as tite lining is cast In place.

As is conventional with open-hearth furnace doors, littlng inps J9 nreprovided on the upper surface of the door. and a furnace inspectionopening H and lining inspection ports 41 are standard fcaturcx Having:described the preferred embodiment of the invention. its operation maybeunderstood readily. Assumlng the door ll is to he placed in position onan activi.` furnace, a water line, not shown. is connected to one of thewater pipe\ 22. the pipe not used leing plugged. Water is introducedinto the pipe 22. which is connected to a hose and flows under pressurethrough conduits 2J into the structural channels t9. Water also flowsthrough the pipe open end 24 into thc jacket lll in the flange portion2l at the bottom section of the door.

From the structural channels I9 the forced circulation water enters thehollow keys 27 through apertures 32 in thc inner face 15, and flowsthrough the keys 27 upwardly and transversely toward the marginal flangcportion 2l ofthe jacket lll. Die water then is fed through the ports 33in the flange t7 into the jacket lli. The vertical keys 29 receive waterfrom the jacket t3 and rctnrn thc water through thc saine slots J4. andthe heated water is forced through thc outlet 35 and removed from Itotil)

thc door by suitable connection with a hose or pipe, not shown.

The` forced circulation of water through thc hollow keys ol the doorwhich are embedded in the refractory material 37 of the lining J3maintains lin,` mctal and rcfiactory material of the door at atcmpclaturc where thc deleterious ellects of the furnace heat nrereduced, thus prolonging the life of the door. 'l'he configuration ofthe rihs affords maximum `support of the refractory lining. and maximumheat exchange between the water and the heated refractory material isalso achieved hy the large contact area provided between the rils andthe refractory lining.

lt is manifest that the above-described embodiment of tite n\cntion ismerely illustrative and that numerous modifications may lc made withinthe spirit und .scope of the invention. Further. it will le understoodthat the .selection of one inlet pip.; andone outlet in the circulationsystem is only an example of one` type of arrangement which may ircoperated tlpott in practicing the invention. and that the invention isnot limited to use with one pipe and one outlet. but that both pipes andoutlets may lc toed in the circulation system simultaneously, or anycombination thereof` \\hat is claimed is:

i. A furnace door comprising an inner plate. an oulcr plate in spacedparallel relation with the inner plate. inarcinal flanccs extending fromthc` plates and rearwardly turncd ith the inncr plate flange encodingfor a first jortoa inwardly and then for a .second portion outwardly tojoin the outcr plate flanpc sealnjtiy. a water jacket defined ly thespaced piatcs and flanges. the inner plat': and its flange first portiondefining a central recess. hollow keys of trapc/nidal cross-section.spaced within the recess and scaled to the inner platt.` and to thcinner plate first flange portion, the keys opening at their ends intothc jacket between the marginal flanges of thc plates. structuralchannels fixed sealingly to th.` inner plate and positioned within thejacket. the channels being in communication with the keys via aperturesthrough the inner platc. the keys within the recess being located toanchor a refrnetory eapalle of being applied in the recess to cover theinner plate and the keys. a water inlet flow connected lo the channelsand in communication with the jacket. and a water outlet connected tothe outer plate and in communication with the jacket vfherehy waterforced through the inlet flows through the channels and to thc jacketsimultaneously. from thc channels to thc keys. and from the keys to theoutlet in the sequence named.

2. A furnace door having a top. sides and a bottom comprising` .spacedinner and outer plates forming between them a water jacket. the plateshaving inwardlyturned flange portions joined together to provide nrccessed inner face on the door with a hollow marginal flangethereabout. a water inlet pipe extending down .said ma ginal tlangc atone side of thc door toward the bottom 1nd having a restricted dischargeterminal at the end thereof .spaced from thc` bottom. a pair of spacedtrnnsvcrsely-extending channels welded to the inner platc inside thewater jacket. cach channel forming a water conduit transversely acrossthe door. a connection for each such conduit to lsaid water inlet pipe.a pair of .spaced hollow keys extending transversely across the recessedinner face ofthe door. each key forming a water conduit that extendscontinuously across the exposed face of thc inner plate, the ends of thchollow keys opening into the hollow flange at each side of thc door, onesuch hollow key being in communication at its center with the conduitprovided by one of .said channels through a port in the` inner platewhereby water from lsaid channel may flow into the hollow key at thc`center and flow laterally into the flange at each side of the door, thcother of said hollow keys hcing in `similar communication with thc otherof said channels, the door also having a hollow vettical key in therecessed area between the two transverselyextending keys which is inflow cow'nunieation with the space between the plates throughoutsubstantially its entire length. a similar vertical key between theupper of the siid tranxverse1yextentling keys and the` marginal tlangcat 'he top of the door in similar tlow eonnnunieation along its lengthwith the space between the two plates. an outlet connection nt the topof the` door and n refractory material lilling the recess and coveringthe keys.

References Cited in the file of this patent U N ITED STATES PATENTSWilliams DCC. 15, 1931 Sticker May 1 |951 Reighart Dec. 16. 195KRobinson Feb. (i, 1962 FOREIGN PATENTS Germany Sept. 27. 1956

1. A FURNACE DOOR COMPRISING AN INNER PLATE, AN OUTER PLATE IN SPACEDPARALLE RELATION WITH THE INNER PLATE, MARGINAL FLANGES EXTENDING FROMTHE PLATES AND REARWARDLY TURNED WITH THE INNER PLATE FLANGE EXTENDINGFOR A FIRST PORTION INWARDLY AND THEN FOR A SECOND PORTION OUTWARDLY TOJOIN THE OUTER PLATE FLANGE SEALINGLY, A WATER JACKET DEFINED BY THESPACED PLATES AND FLANGES, THE INNER PLATE AND ITS FLANGE FIRST PORTIONDEFINING A CENTRAL RECESS, HOLLOW KEYS OF TRAPEZOIDAL CROSS-SECTIONSPACED WITHIN THE RECESS AND SEALED TO THE INNER PLATE AND TO THE INNERPLATE FIRST FLANGE PORTION, THE KEYS OPENING AT THEIR ENDS INTO THEJACKET BETWEEN THE MARGINAL FLANGES OF THE PLATES, STRUCTURAL CHANNELSFIXED SEALINGLY TO THE INNER PLATE AND POSITIONED WITHIN THE JACKET, THECHANNEL BEING IN COMMUNICATION WITH THE KEYS VIA APERTURES THROUGH THEINNER PLATE, THE KEYS WITHIN THE RECESS BEING LOCATED TO ANCHOR AREFRACTORY CAPABLE OF BEING APPLIED IN THE RECESS TO COVER THE INNERPLATE AND THE KEYS, A WATER INLET FLOW CONNECTED TO THE CHANNELS AND INCOMMUNICATION WITH THE JACKET,